ES2860455T3 - Thermal coating for protective clothing - Google Patents

Abstract

A thermal coating (60) for protective suit (10) comprising: a non-woven (62) having 15-30% by weight of polybenzimidazole fiber, the remainder is an aramid fiber, the non-woven, which excludes wool and cellulosic fibers, and having a thickness less than 3 mm and a basis weight less than 2.9 osy (100 g / m2).

Description

DESCRIPTION

Thermal coating for protective clothing

Field of the invention

The present invention is directed to a thermal liner for use in, for example, protective clothing. Background of the invention

Protective garments are now well known for their many and varied uses, such as suits for industrial workers, firefighters, forest firefighters, race car drivers, airplane pilots, and military personnel. The garments include not only full body suits, but also individual garments such as pants, jackets, gloves, boots, hats, caps, masks, etc. Protective clothing is generally designed to protect the user from a variety of environmental hazards. Firefighter clothing is representative of such protective clothing.

Firefighter garments, generally known as protective gear, are designed primarily to prevent the firefighter from being seriously burned. A second major threat to firefighters is heat stress. Each year more firefighter deaths occur in the United States from heat stress-related conditions than from burns. Conditions related to heat stress include elevated core body temperature leading to heat prostration, increased blood pressure, heat stroke, and sometimes heart attack. As this second threat has been recognized, the fire service community has sought to modify and improve protective equipment to minimize its contribution to heat stress. Protective equipment generally includes a coat and overalls. Protective gear generally consists of three layers: an outer shell, a moisture barrier, and a thermal barrier. The outer shell is typically a woven fabric made of flame resistant fibers and is considered the firefighter's first line of defense. Not only must it resist flames, it must be strong and durable so that it will not break, unduly wear or snag during normal firefighting activities.

The moisture barrier layer, while also flame resistant, is provided to prevent water from penetrating and saturating the protective gear. Excess humidity in the environment would load the firefighter with additional weight and therefore increase his load. Such increased load is likely to increase the possibility of heat stress.

The thermal barrier coating is also flame resistant and offers most of the thermal protection offered by the set. A traditional thermal barrier coating includes an insulating layer of flame resistant fibers padded to a lightweight woven cloth also made of flame resistant fibers. A material commonly used as a component in thermal barrier, and often considered an industry standard, is known as E89® from DuPont of Richmond, VA. E89 is a hydroentangled nonwoven material consisting of a NOMEX® (meta-aramid) staple or a KEVLAR® (para-aramid) staple or a combination of both, NOMEX® Brand Fiber Technical Guide, H-52720 Revised in July 2001 by DuPont, Richmond VA, page 3.

While E89 is an excellent material, there is a need to find better materials, that is, materials with the same or better thermal protection and lower weights.

Nonwovens used in thermal layers have been suggested and are described in US Patents 4937136, 5136723, 5236769, 6430754, 6743498, 7676855 and US Publication 2002/0069453.

Document US4937136 teaches an inner thermal lining made with a nonwoven fabric of a blend of wool and a synthetic fiber capable of operating at high temperatures. Synthetic fibers include, but are not limited to, NOMEX, KEVLAR, and polybenzimidazole (PBI).

US5136723 teaches an internal thermal barrier made with a mesh fabric (with vents) from NOMEX or KEVLAR that has a basis weight of approximately 2 osy (ounces per square yard) or 67.8 g / m2 (grams per square meter) . This mesh fabric is believed to be E89.

US5236769 teaches a nonwoven textile layer made with 100 % aramides, blends of 50% wool and thermoset fiber, such as PBI. This nonwoven has a basis weight of 200 g / m2 (5.9 osy) with a thickness of 4 mm.

US2007 / 0137012 is directed to a thermal protection fabric that includes a composition of inherently flame resistant fibers and interstices having insulating air pockets.

Document US6407019 is directed, among other things, to an insulating liner made of at least one two-layer non-woven in which each non-woven layer has a basis weight of 80 g / m2.

WO 01/66193 describes, among other things, a thermal liner made from an aramid nonwoven of PBI materials.

US6430754 teaches a second layer of 50.8 g / m2 (1.5 osy) E89 insulating material or a hydroentangled nonwoven of a blend of aramid fibers and PBI. US6430754 further teaches an alternative embodiment in which the thermal barrier has a first layer of E89 of 78.0 g / m2 (2.3 osy) (hydroentangled nonwoven) and a second layer of E89 of 50.8 g / m2. m2 (1.5 osy) (hydroentangled nonwoven).

US6743498 teaches an insulating barrier of a perforated nonwoven that has a basis weight in the range of 100-200 g / m2 and is made from a variety of thermoset fibers including, but not limited to, aramids and PBI.

US767855 teaches an insulating layer of a nonwoven made of, among other things, aramides or melamine (but not PBI), the nonwoven can be water jet bonded and the basis weight of the nonwoven can be in the range of 25.4-271.2 g / m2 (0.75-8 osy). In the illustrative examples, the nonwoven is 84.8 g / m2 (2.5 osy) and is made from 50% BASOFIL® melamine / 25% meta-aramid / 25% para-aramid.

US publication 2002/0069453 teaches the insulation layer comprising a blend of inherently hydrophobic fibers and non-hydrophobic flame resistant fibers. Hydrophobic fibers include polytetrafluoroethylene (PTFE) fibers. Non-hydrophobic fibers include aramid fibers, PBI fibers, polybenzoxazole (PBO) fibers, melamine fibers, and mixtures thereof.

Summary of the invention

The present invention provides a thermal liner for protective suits comprising: a nonwoven having 15-30% by weight of polybenzimidazole fiber, the balance being an aramid fiber, the nonwoven excluding wool and cellulosic fibers, and which is less than 3 mm thick and has a basis weight of less than 2.9 osy (100 g / m2). Advantageously, the protective suit is a firefighter's protective equipment.

In one embodiment, the nonwoven for use in thermal coating, for example, for use in protective suits, includes 15-30% by weight of polybenzimidazole fiber as the first inherently heat resistant fiber, and a balance of aramid fiber. as a second heat resistant fiber. The nonwoven excludes wool and has a thickness of less than 3 mm and a basis weight of less than 100 g / m2 (2.9 osy). In another embodiment, the thermal protective suit liner includes a nonwoven that includes an inherently flame resistant fiber and fibers that are inherently resistant to moisture absorption. Inherently flame resistant fiber is different from said inherently resistant fiber to moisture absorption. The nonwoven has equivalent or better thermal protection performance (TPP) and lower basis weight than an industry standard nonwoven consisting of a para-aramid or meta-aramid nonwoven or a mixture of both.

In an example of the thermal coating, the first inherently heat resistant fiber and the second heat resistant fiber have a water retention of less than 15%.

In one example of the thermal liner, said nonwoven is a perforated hydroentangled nonwoven.

In yet another example, the thermal liner further comprises an oriented fabric affixed to said nonwoven.

In yet another example, the thermal liner further comprises multiple nonwovens.

In accordance with another aspect, the present invention provides a protective garment comprising a nonwoven thermal liner according to any of the examples described above.

Description of the drawings

In order to illustrate the invention, data from various embodiments of the invention are depicted in the figures; it is understood, however, that this invention is not limited to the data shown and that this data has not necessarily been optimized, but only indicates the possibilities of the inventive materials.

Figure 1 is an illustration of a protective garment with broken parts.

Figure 2 is an exploded view of the layers of the protective garment shown in Figure 1.

Description of the invention

With reference to the figures, in which the same numbers refer to similar elements, a protective garment 10 is shown in Figure 1. Specifically, the protective garment 10 is the jacket of a firefighter protective suit. It is understood, however, that the invention is not limited to firefighter protective equipment. The invention can be used in other types of protective equipment, as will be apparent to those skilled in the art. Such other types of protective suits include, but are not limited to, suits for industrial workers (including, for example, arc flash clothing), forest firefighters, race car drivers, aircraft pilots, military personnel, and the like. .

As indicated in Figures 1 and 2, the protective garment 10 may have a multilayer construction that includes an outer shell 20, a moisture barrier 40, and a thermal liner 60. The outer shell 20 is typically constructed of a abrasion and flame resistant material comprising flame resistant fibers made of, for example, aramid (meta- and / or para-aramid), polybenzimidazole (PBI), polybenzoxazole (PBO), melamine or the like and mixtures of the same themselves. The outer shell 20 may be treated with a water resistant finish (eg, a perfluorohydrocarbon) to prevent or reduce the absorption of water from the outside environment. The weight of the outer shell material can be in the range of about 203.4-271.2 g / m2, that is, 6-8 ounces per square yard (osy).

The moisture barrier 40 may be constructed of a nonwoven or woven fire resistant fabric 42 comprising flame resistant fibers made of, for example, aramid (meta- and / or para-aramid), polybenzimidazole (PBI), polybenzoxazole (PBO), melamine or the like and mixtures thereof. The moisture barrier 40 can be laminated with a waterproof layer 44 of material such as, for example, a layer of polytetrafluoroethylene (PTFE) or polyurethane (PU). When such an impermeable layer 44 is provided, it is typically provided over the moisture barrier 40 so that it faces the thermal coating 60. The weight of the moisture barrier material is typically within the range of about 135 , 6-203.4 g / m2 (4-6 osy).

Thermal liner 60 can optionally include both an insulation layer 62 and a cloth layer 64, which can be padded together. In alternative embodiments, however, insulation layer 62 alone can be used. Insulation layer 62 is discussed in more detail below. When used, the cloth layer 64 can be constructed of woven material comprising flame resistant fibers made of, for example, aramid (meta-aramid or para-aramid), polybenzimidazole (PBI), polybenzoxazole (PBO), melamine, cellulosic flame resistant (FR) compounds, modacrylic, carbon or the like, and mixtures thereof. The cloth layer 64 may optionally be finished with a hydrophilic finish that draws perspiration from the firefighter's body, if desired. The material weight of the cloth layer is normally in the range of about 33.9-203.4 g / m2 (1-6 osy).

Insulation layer 62 comprises a nonwoven material comprising a plurality of flame resistant fibers, which are described in greater detail below. The insulation layer 62 may comprise a single nonwoven layer, or two nonwoven layers, or multiple nonwoven layers. In one embodiment, the insulation layer has two layers of nonwoven material and each of these layers can have a different basis weight. The nonwoven can be in a weight range of about 25.4-271.2 g / m2 (0.75-8 osy). In one embodiment, the nonwoven can be in a weight range of about 39.9-101.7 g / m2 (1.0-3.0 osy). In another embodiment, the nonwoven may be in a weight range of 40.7-84.8 g / m2 (1.2-2.5 osy). In yet another embodiment, the nonwoven may be in a weight range of 40.7-67.8 g / m2 (1.2-2.0 osy). In yet another embodiment, the insulation layer may comprise two non-woven layers, one layer with a basis weight of about 47.5 g / m2 (1.4 osy) and the other layer with a basis weight of about 61.0 g. / m2 (1.8 osy). In one embodiment, the nonwoven material can have a thickness of less than 2mm. In another embodiment, the nonwoven material can have a thickness of less than 1mm. The non-woven material, in all modalities, must have a minimum thickness of 0.25 mm. In yet another embodiment, the nonwoven may have a thickness in the range of about 0.75-1.25mm. The non-woven material can be manufactured by any non-woven process. Such processes include, but are not limited to, wet-laid, air-laid, carding, felting, punching, and hydroentangling (hydroentangling). In one embodiment, the nonwoven can be hydroentangled. The non-woven material can be smooth (ie without openings), perforated (see US5136723), dimpled (see US7676855), or a combination of any of the above.

The nonwoven can comprise a plurality of flame resistant fibers. The nonwoven can exclude any wool and / or cellulosic fibers and / or natural fibers (ie, any non-synthetic or non-man-made fibers). The nonwoven can be characterized as having equivalent or better thermal protection performance (TPP per NFPA 1971 (2007)) and lower basis weight than an industry standard nonwoven consisting of a paraaramid or meta-aramid nonwoven. or a mixture of both, for example - E89.

In one embodiment, the flame resistant fibers can be further characterized as non-water absorbing fibers. Fiber that does not absorb water is not recommended for reclaiming moisture from the fiber. Moisture recovery, as used in the present description, refers to the percentage of atmospheric moisture in a material textile that equilibrates with a standard atmosphere after partial drying, calculated as a percentage of the moisture-free weight. In contrast, fiber that does not absorb water refers to the ability of the fibers, when they come into contact with liquid water, to swell, absorb and retain that water. The water absorbency of the fibers can be measured according to ASTM D2402 (2012). The maximum water retention that can be tolerated is less than 15%.

The first inherently heat resistant fiber of the nonwoven is selected from the group consisting of polybenzimidazoles.

The second heat resistant fiber of the nonwoven material is selected from the group of aramids (meta and / or paraaramides).

Examples

The following examples further illustrate the invention; it is understood, however, that this invention is not limited to the precise formulations set forth.

In Table 1, several representative embodiments of the present invention are shown in comparison to certain industry standard materials. These embodiments illustrate a range of basis weights and thicknesses that can be useful in the manufacture of protective equipment. The AB fiber blends represent inventive embodiments and the C fiber blend represents an industry standard material.

Table 1

In TABLE 2, various full compound comparisons of the industry standards of the present invention are shown. Full compound refers to protective equipment with an outer shell, a moisture barrier, and a thermal liner. The outer shell was PBI MATRIX® available from Safety Components, Inc of Greenville, SC. The moisture barrier was CROSSTECH 2C available from WL Gore & Elkton Associates, MD. The thermal barrier was not padded and was made with a NOMEX cloth and the insulation layers listed in TABLE 2. The first two materials listed are existing industry standard constructions and the remainder are examples of the present invention.

Table 2

In TABLE 3A-D, various comparisons of whole compounds of the present invention to various industry standard whole compounds are shown. Full compound refers to protective equipment with an outer shell, a moisture barrier, and a thermal liner. The outer shell was varied as indicated. The moisture barrier was varied as indicated. The thermal barrier was padded and varied as indicated.

Table 3a

Table 3b

Table 3c

3d table

Claims (8)

1. A thermal liner (60) for protective suit (10) comprising: a nonwoven (62) having 15-30% by weight of polybenzimidazole fiber, the remainder is an aramid fiber, nonwoven, which excludes wool and cellulosic fibers, and having a thickness of less than 3 mm and a basis weight of less than 2.9 osy (100 g / m2). The thermal coating (60) according to claim 1, wherein the polybenzimidazole fiber is a first inherently heat resistant fiber and the aramid fiber is a second heat resistant fiber. The thermal coating (60) according to claim 2, wherein the first inherently heat resistant fiber and the second heat resistant fiber have a water retention of less than 15%, as measured by ASTM D2402 (2012 ). The thermal liner (60) according to any of claims 1 to 3, wherein the protective suit (10) is a firefighter protective equipment. The thermal liner (60) according to any one of claims 1 to 4, wherein said nonwoven (62) is a perforated hydroentangled nonwoven. The thermal liner (60) according to any of the preceding claims, further comprising an oriented fabric (64) that is attached to said nonwoven (62). The thermal liner (60) according to any of the preceding claims, further comprising multiple nonwovens (62). A protective garment (10) comprising a thermal liner (60) according to any one of claims 1 to 7 above.